ECTROPION:
A type of eyelid malposition, called ectropion, can occur due to a number of factors, the most common of which include: age (loss of skin elasticity), scarring (due to previous surgery), mechanical (due to eyelid/facial tumor), or paralytic (loss of muscle tone).
Regardless of the cause, ectropion, or an eyelid that is being pushed out or everted, can have deleterious effects on the cornea, which can lead to permanent vision loss. Treatment of ectropion is necessary (usually by surgical measures) to prevent dangerous downstream effects.